Many patent claims use word like “substantially” or “basically” or “fundamentally” as a proviso to a more absolute term, particularly in relation to shapes. You often see phrases like “substantially circular” or “generally rectangular” in order to describe a shape which has a particular shape but to prevent an overly narrow interpretation where a decision maker says that the shape “must be” that shape and no deviation is allowed.
Many jurisdictions have issues with relative terms such as those given above. Previously, Europe was one place where the terms could be used and no objection would be raised as it was generally understood that while being a broad expression, the terms “substantially” as well as its synonyms “basically” or “fundamentally” were unambiguous for a person skilled in the art.
However, a decision of the European Patent Office Board of Appeals T 0971/10 of 25 August 2011 has cast some doubt on the allowability of the use of these relative terms.
The decision was based around an appeal from a decision of the Examining Division which said that the pending sets of claims did not comply with the requirements of Article 84 EPC due to the use of the expressions “substantially” and “normally” in conjunction with the terms “circular”, “along a radius”, “vertical” and “conforming”.
The Board of Appeals agreed with the Examiner, denied the appeal and remitted the case to Examining Division for further prosecution.
The take home message is include these relative terms, but you should also ensure that fall back positions are included for the jurisdictions that don’t like the relative terms.
The full decision can be accessed here: http://www.epo.org/law-practice/case-law-appeals/recent/t100971eu1.html